In this application support is requested for continuation of our methodological studies, and for experimental neuroanatomical investigators aimed at improving our knowledge of the organization of the basal forebrain in mammals. In the methodological studies we are primarily concentrating our efforts to develop a solid HRP-technique, that can be successfully combined with degeneration methods or autoradiography on the electronmicroscopic level. The study of basal forebrain organization is concerned with three mutually interrelated subjects: 1) the internal organization of the afferent and efferent connexions of the olfactory cortex; 2) the olfacto-amygdalo-hypothalamic relations, and 3) the ventral strio-pallidal system. The experimental analysis is aided by a combination of various light- and electron microscopic tracing techniques, including the Golgi method, degeneration methods, the autoradiographic technique and different horseradish peroxidase methods.